The investigation of flow instabilities on a rotating disk with curvature in the radial direction

The major objective is to explore any visible differences of the flow field with wall curvature of the test body, including possible interaction between Taylor-Gortler instabilities present along concave walls and the inflexional instabilities investigated here. An experimental study was conducted with emphasis placed on making visual observations and recording photographically the flow instabilities present under three different rotating bodies: a flat disk, a concave paraboloid, and a convex paraboloid. The data collected for the three test bodies lead to the conclusion that the wall curvature of the concave and convex paraboloids did not alter the observed flow field significantly from that observed on the flat disk

Subsonic high-angle-of-attack aerodynamic characteristics of a cone and cylinder with triangular cross sections and a cone with a square cross section

Experiments were conducted in the 12-Foot Pressure Wind Tunnel at Ames Research Center on three models with noncircular cross sections: a cone having a square cross section with rounded corners and a cone and cylinder with triangular cross sections and rounded vertices. The cones were tested with both sharp and blunt noses. Surface pressures and force and moment measurements were obtained over an angle of attack range from 30 deg to 90 deg and selected oil-flow experiments were conducted to visualize surface flow patterns. Unit Reynolds numbers ranged from 0.8x1,000,000/m to 13.0x1,000,000/m at a Mach number of 0.25, except for a few low-Reynolds-number runs at a Mach number of 0.17. Pressure data, as well as force data and oil-flow photographs, reveal that the three dimensional flow structure at angles of attack up to 75 deg is very complex and is highly dependent on nose bluntness and Reynolds number. For angles of attack from 75 deg to 90 deg the sectional aerodynamic characteristics are similar to those of a two dimensional cylinder with the same cross section

Dietary calcium intake and adiposity in children and adolescents: Cross-sectional and longitudinal results from IDEFICS/I.Family cohort

Background and aims: Studies in children and adolescents suggest that higher dairy consumption may exert a protective effect on adiposity. However, only few studies examined the association between dietary calcium intake and body mass measures with conflicting results. We evaluated the association between total dietary calcium, calcium from dairy and non-dairy sources and anthropometric indices in a large European cohort of children and adolescents. Methods and Results: As many as 6, 696 children belonging to the IDEFICS study were eligible for the cross-sectional analysis (Boys = 51%; age 6.0 ± 1.8 years; mean ± SD). Of these, 2, 744 were re-examined six years later (Boys = 49.6%; age = 11.7 ± 1.8 years) in the framework of the I.Family study. The exposures were the baseline energy-adjusted total, dairy and non-dairy calcium intakes measured by a validated 24-h dietary recall. Multivariable linear regression was used to determine the association between calcium intake and z-scores of anthropometric indices (body mass index, BMI; waist circumference, WC; sum of skinfolds, SS; fat mass index, FMI) at baseline, and their variation over the 6 years follow-up. The association of dietary calcium with the incidence of overweight/obesity was also assessed. At baseline, an inverse association between total calcium intake and all the adiposity indices was consistently observed in boys, while only SS and FMI were significant in girls. The prevalence of overweight/obesity decreased significantly (P < 0.0001) across tertiles of calcium intake, in both sexes. Over the follow-up, boys with higher baseline calcium intake value showed significantly lower increase in BMI, WC and FMI z-scores, while in girls only a lower increase in WC z-score was observed. Only in boys, the risk to become overweight/obese decreased significantly across tertiles of calcium intake. Similar results were observed by analyzing only dietary calcium from dairy, while no association was observed between non-dairy calcium and adiposity indices. Conclusions: We showed in a large cohort of European children and adolescents that dietary calcium intake may play a role in the modulation of body fat in developmental age. The association between dietary calcium and adiposity indices was driven by dairy calcium, while no effect was observed for non-dairy calcium intake. The existence of a sex-related difference in the association deserves further investigations

Predictive associations between lifestyle behaviours and dairy consumption: The IDEFICS study

Background and aim: Physical activity (PA) and sedentary behaviours (SB) are related to obesity and cardiometabolic risk; however, the literature is controversial regarding the effect of dairy consumption on the development of cardiovascular disease (CVD) risk factors. The aim of this study was to assess longitudinally the relationship between specific lifestyle behaviours (PA and SB) and dairy consumption in a sample of European children and adolescents. Methods and results: Children from the IDEFICS study were included in the analyses. Two measurements, with 2 years'' interval, were conducted. A total of 1688 (50.8% boys) children provided information regarding diet, measured by a 24-h dietary recall, PA measured by accelerometers and parent-reported sedentary screen time (SST) at both time points. Different combinations of these behaviours, at each survey and over time, were derived applying specific recommendations. Multilevel ordinal logistic regression and analysis of covariance were used to assess their association with dairy consumption, adjusted for potential confounders. Differences by gender were found regarding dairy product consumption and also adherence to SB and PA recommendations at T0 and T1. Children meeting both lifestyle recommendations, at the two measurement points, had higher probability to consume more milk and yogurt and less cheese than the rest of combinations. Conclusions: These results suggest that European children with a healthy lifestyle, especially regarding PA and SB over time, consumed more milk and yogurt. This study suggests that the protective effect of specific dairy products found in literature could be partially due to the association of their consumption with specific healthy lifestyles

Dairy consumption at snack meal occasions and the overall quality of diet during childhood. Prospective and cross-sectional analyses from the IDEFICS/I.Family cohort

There is scarce information on the influence of dairy consumption between main meals on the overall diet quality through childhood, constituting the main aim of this research. From the Identification and prevention of Dietary-and lifestyle induced health EFfects In Children and infantS (IDEFICS) study, and based on the data availability in each period due to drop outs, 8807 children aged 2 to 9.9 years from eight European countries at baseline (T0: 2007–2008); 5085 children after two years (T1); and 1991 after four years (T3), were included in these analyses. Dietary intake and the Diet Quality Index (DQI) were assessed by two 24 hours dietary recalls (24-HDR) and food frequency questionnaire. Consumption of milk and yogurt (p = 0.04) and cheese (p < 0.001) at snack meal occasions was associated with higher DQI scores in T0; milk and yogurt (p < 0.001), and cheese (p < 0.001) in T1; and cheese (p = 0.05) in T3. Consumers of milk (p = 0.02), yogurt (p < 0.001), or cheese (p < 0.001) throughout T0 and T1 at all snack moments had significantly higher scores of DQI compared to non-consumers. This was also observed with the consumption of cheese between T1 and T3 (p = 0.03). Consumption of dairy products at snack moments through childhood is associated with a better overall diet quality, being a good strategy to improve it in this period

Chiral Perturbation Theory Predictions for η→π+π−π0γ\eta \to \pi^+ \pi^- \pi^0 \gamma

The $\eta \to \pi^+ \pi^- \pi^0 \gamma$ decay is discussed in the general context of Chiral Perturbation Theory (ChPT), assuming that the low--energy constants (counter--terms) are saturated by vector-meson resonances. The $\eta \to \pi^+ \pi^- \pi^0 \gamma$ amplitude can be separated in two distinct pieces: the inner bremsstrahlung, $A^{(IB)}$, and the structure dependent (or direct emission), $A^{(SD)}$, amplitudes. The former -- which essentially contains the same physics as $A(\eta \to \pi^+ \pi^- \pi^0)$ -- is found to dominate over the second one -- which looks more interesting from the ChPT point of view.Comment: 14 pages, 4 figures. PS file (96/8 N/P) available at http://www.nordita.dk/locinfo/preprints.htm

Percentile reference values for anthropometric body composition indices in European children from the IDEFICS study

INTRODUCTION: To characterise the nutritional status in children with obesity or wasting conditions, European anthropometric reference values for body composition measures beyond the body mass index (BMI) are needed. Differentiated assessment of body composition in children has long been hampered by the lack of appropriate references. OBJECTIVES: The aim of our study is to provide percentiles for body composition indices in normal weight European children, based on the IDEFICS cohort (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS). METHODS: Overall 18 745 2.0-10.9-year-old children from eight countries participated in the study. Children classified as overweight/obese or underweight according to IOTF (N = 5915) were excluded from the analysis. Anthropometric measurements (BMI (N = 12 830); triceps, subscapular, fat mass and fat mass index (N = 11 845-11 901); biceps, suprailiac skinfolds, sum of skinfolds calculated from skinfold thicknesses (N = 8129-8205), neck circumference (N = 12 241); waist circumference and waist-to-height ratio (N = 12 381)) were analysed stratified by sex and smoothed 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile curves were calculated using GAMLSS. RESULTS: Percentile values of the most important anthropometric measures related to the degree of adiposity are depicted for European girls and boys. Age-and sex-specific differences were investigated for all measures. As an example, the 50th and 99th percentile values of waist circumference ranged from 50.7-59.2 cm and from 51.3-58.7 cm in 4.5-to < 5.0-year-old girls and boys, respectively, to 60.6-74.5 cm in girls and to 59.9-76.7 cm in boys at the age of 10.5-10.9 years. CONCLUSION: The presented percentile curves may aid a differentiated assessment of total and abdominal adiposity in European children

Reexamining radiative decays of 1−−1^{--} quarkonium into η′\eta' and η\eta

Recently CLEO has studied the radiative decay of $\Upsilon$ into $\eta'$ and an upper limit for the decay has been determined. Confronting with this upper limit,most of theoretical predictions for the decay fails. After briefly reviewing these predictions we re-examine the decay by separating nonperturbative effect related to the quarkonium and that related to $\eta'$ or $\eta$, in which the later is parameterized by distribution amplitudes of gluons in $\eta'$. With this factorization approach we obtain theoretical predictions which are in agreement with experiment. Uncertainties in our predictions are discussed. The possibly largest uncertainties are from relativistic corrections for $J/\Psi$ and the value of the charm quark mass. We argue that the effect of these uncertainties can be reduced by using quarkonium masses instead of using quark masses. An example of the reduction is shown with an attempt to explain the violation of the famous 14% rule in radiative decays of charmonia.Comment: 9 Pages, Latex fil

Polymorphic Allele of Human IRGM1 Is Associated with Susceptibility to Tuberculosis in African Americans

An ancestral polymorphic allele of the human autophagy-related gene IRGM1 is associated with altered gene expression and a genetic risk for Crohn's Disease (CD). We used the single nucleotide polymorphism rs10065172C/T as a marker of this polymorphic allele and genotyped 370 African American and 177 Caucasian tuberculosis (TB) cases and 180 African American and 110 Caucasian controls. Among African Americans, the TB cases were more likely to carry the CD-related T allele of rs10065172 (odds ratio of 1.54; 95% confidence interval, 1.17–2.02; P<0.01) compared to controls. Our finding suggests that this CD-related IRGM1 polymorphic allele is also associated with human susceptibility to TB disease among African Americans

Further Experimental Studies of Two-Body Radiative \Upsilon Decays

Continuing our studies of radiative Upsilon(1S) decays, we report on a search for Upsilon to gamma eta and Upsilon to gamma f_{J}(2220) in 61.3 pb^{-1} of e^{+}e^{-} data taken with the CLEO II detector at the Cornell Electron Storage Ring. For the gamma eta search the three decays of the eta meson to pi^{+}pi^{-}pi^{0}, pi^{0}pi^{0}pi^{0}, and gamma gamma were investigated. We found no candidate events in the two (3\pi)^{0} modes and no significant excess over expected backgrounds in the gamma gamma mode to set a limit on the branching fraction of B(Upsilon to gamma eta) < 2.1 x 10^{-5} at 90% C.L. The three charged two-body final states h h-bar (h = pi^{+}, K^{+}, p) were investigated for f_{J}(2220) production, with one, one, and two events found, respectively. Limits at 90% C.L. of B(\Upsilon to gamma f_{J}) x B(f_{J} to h h-bar) ~ 1.5 x 10^{-5} have been set for each of these modes. We compare our results to measurements of other radiative Upsilon decays, to measurements of radiative J/psi decays, and to theoretical predictions.Comment: 19 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review